I have a question for anyone that might know. I just bought a 2005 F150 with the small V8 for gas mileage reasons. I put the Gibson exaust on it and got the Superchips tuner hoping that this would not only increase gas mileage but also make it a little faster if I required it. However, it hasnt done really anything, I mean I can tell it is a tad faster, but anything more than half throttle is worthless. It sounds like the RPMs are jumping way up but it isnt going any faster between flooring it and pushing the gas half way down. I am sure I sound really ignorant, but this is the first vehicle I have tried to do anything to in my life besides my old F100 that I spent every weekend fixing. So the question is, I drove a King ranch version of my truck the other day and it was incredible faster than mine, not to mention my Tahoe is much faster than my truck, and I cant have my wife out running me. Someone told me that the rear Diff is the trick to fixing my problem. Can someone please confirm that this is the way to go, and perhaps give some Ideas on how else to increase spead without sacrificing gas mileage.

Sorry for the lengthy message, I just wanted to make sure I got the whole story out there.

 

The problem you're having most likely isn't from your rear axle. It's most likely a 3:55, I don't know if L/S or not. Either way.... For the power your looking for, like a King Ranch 5.4, or a Tahoe 5.3. You're going to need a bigger V-8.

Although their are various waysto upgrade your 4.6 V-8, I still don't think you'll be happy with it unless you're looking to spend a couple grand.

Good luck with your truck, may not have the power. But I've heard 4.6 Liters are VERY good engine's.

Peace

 

I dont have a problem with spending a couple grand if I have to, although it is disappointing since I probably should have just gotten the larger V8.

What can I do and what should I expect in terms of Gas mileage and power?

 

In all honesty, I'm not REALLY farmiliar with the 4.6 V-8. Other than what friends have said, and previous knowledge from this site. You could do a search for 4.6 Performance Upgrades. I haven't heard of many people supercharging a 4.6, because I don't think it has enough low end to handle it. But other than Exhaust Modifications, Engine Chips, And Various Small Engine tweaks such as Cold Air Intakes. I'm not sure what else you could do (Obviously there are many more things, I just don't know them )

You could get your gear ratio adjusted more for accelleration; or your rear end to something like 3:75 posi.

Sorry I couldn't be more help, and even so, I've heard the Brand new 5.4V-8's STOCK aren't as fast as anything else in comparison anyway. Ford didn't seem to think that performance, or having that 1 second faster on the quarter mile was a big problem. But at least you're In a Ford right?

 

I am going through the same thing with my 4.6(I should've bought the 5.4 to). I have an STX with 3.55 non LS.
Some things you could do, although it will cost more than a couple of grand.
1. Boost Turbo or SCer, either will help.
2. ported heads
3. cams
4. intake manifold swap
5. headers w/ full exhaust
6. E-fans
7. electric water pump
8. gears (I have 3.55s and am swapping to 4.10s and adding Detroits Lockers TrueTrac LS diff)
9. shift kit
I have read many magazines about people getting 300-390 reliable N/A HP out of 4.6s, its just how much you want to spend and how reliable it will be.
Supposedly these 2v 4.6s are very strong, its just getting the power out of them is whats not so simple.
Hope this helps
Later
M V

 

I would get some 4.10's in the rear. Yes it will decrease your gas mileage a tad but don't fear the gear. Your engine rpms will be slightly higher. Also look into getting another intake. Airforce 1, K&N, etc. Oh and never buy a mod thinking you will get better gas mileage....your setting yourself up for a heartache.

 

I just went from an 02 f150 4x4 5.4 3.55 ls to an 06 f150 4x4 5.4 4.10 ls and it is day and night difference. My 02 would do EXACLEY what you said......put it to the floor and it would make all kinds of rpm noise but not go anywhere. With this new one (exact same weight even)......I can smoke the tires! All the difference in the world.......may still have my other one had I only known! Gordon

 

Slap a Procharger Supercharger on it. they make one just for the 4.6L. I have a huge stack of papers from them on it because i was looking into for my 4.6.....check it out. Its only thing other then buying a truck that will give you a noticable difference.

 

I dont think they have made superchargers for the 2004+ 4.6s